Un fisiologo, biologo e chimico olandese, Jan Ingenhousz, è stato colui che ha mostrato che la luce del sole è essenziale per le piante.

Era meglio conosciuto per la sua scoperta nella fotosintesi. Ha mostrato che la luce del sole è essenziale per il processo di fotosintesi per procedere con cui le piante verdi assorbono l'anidride carbonica e l'ossigeno viene rilasciato fuori, nell'atmosfera.

Nel primo esperimento della giara Bell di Joseph Priestley (1772), si concluse che le piante restituiscono all'aria ciò che gli animali che respirano o le candele accese rimuovono, che egli chiamò aria deflogistica, poi chiamata ossigeno da Jan Ingenhousz.

Jan Ingenhousz tried to prove in the 1770s that plants too had a gaseous exchange.The thought of proving plants to have a gaseous exchange came in his mind when he met Priestley.

Ingenhousz & Benjamin Franklin stayed with a polymath and a botanist Rev. John Mitchell in Thornhill ,Yorkshire where they pursued the idea of gaseous exchange in plants based on findings of Priestley that plants make and absorb gaseous.

In 1779,Ingenhousz found while experimenting with the aquatic plant Hydrilla, that bubbles were exerted from the green parts of plant in presence of light whereas the bubbles stopped in the dark.(light decreased so no bubble formation.)These bubbles were identified as Oxygen.

The above picture shows photosynthesis forming bubbles on a plant underwater (left) and the apparatus (right).

Later on ,it was also discovered that some of the mass of plants comes from the air and not only the water & nutrients in the soil because it was observed that plants give carbon dioxide in dark hence the amount of oxygen given in the light is more than that given in dark.

From his experiment ,he found that :

1. Light is important for the restoration.(photosynthesis)
2. The green parts of the plant can only perform photosynthesis.
3. The damaging effect of all the living parts of plant that damage air (respire) is neutralized by the extent of the air restoration by green plants.

Hope this will help you.

Thank you ?.